A Scanning Electron Microscope Study of Intratubular Dentin Fibers

Dentinal tubules have generally been considered to be occupied only by the cytoplasmic processes of odontoblasts. Recently, however, JOHANSEN and PARKS [1] and FRANK [2] found unmineralized collagen fibers along with the odontoblastic process in dentinal tubules. JAMES [3] failed to find odontoblastic processes in the peripheral parts of the dentinal tubules in his histochemical study and this was confirmed by BRÄNNSTRÖM and GARBEROGLIO [4]. According to FURSETH and MJÖR [5], only an amorphous substance and collagen fibrils were observed in the obturated dentinal tubules in the cortico-steroid covered dentin. Based on these reported studies, there could be a relationship between the appearance of collagen fibers in the dentinal tubule and disappearance of the cytoplasmic process.The present report deals with the intratubular structures observed in the dentinal tubules with a scanning electron microscope.